Hi, Nice To Know There Are People Who Are Up

Hi, nice to know there are people who are up this late. I am a nurse that works nights, so, when I am off from work, I can't sleep. However, my daughter in law is wanting to get pregnant. This will be her third pregnancy. She has one 3 year old female and one month ago after taking injections of progesterone she miscarried in her 5th week. She is 33 years old. She has regular menstrual cycles,. I did not know of her taking injections. Of course, my days of having babies are over. I told her just give it time. I believe she got off birth control 3 months ago. I aborted a set of twins at 12 weeks. I gave her this advise. Relax and count 9 days from the first day of her cycle and she should ovulate around that time. Egg stays alive about 24 hours, sperm 72. Since I miscarried 33 years ago, my wait time was 3 months and I counted 9 days after I started my period and it worked. Did I give her good info on time of ovulation? Count backwards because that period is preparing for next egg?